'data.frame': 1599 obs. of 12 variables:
$ fixed.acidity : num 12.7 9.8 6.5 8.6 7.5 7.6 10.1 6.4 6.1 6.7 ...
$ volatile.acidity : num 0.6 0.66 0.88 0.52 0.58 0.5 0.935 0.4 0.58 0.46 ...
$ citric.acid : num 0.49 0.39 0.03 0.38 0.14 0.29 0.22 NA 0.23 0.24 ...
$ residual.sugar : num 2.8 3.2 NA 1.5 2.2 2.3 3.4 1.6 2.5 1.7 ...
$ chlorides : num 0.075 0.083 0.079 0.096 0.077 NA 0.105 0.066 0.044 0.077 ...
$ free.sulfur.dioxide : num 5 21 23 5 27 5 11 5 16 18 ...
$ total.sulfur.dioxide: num NA 59 47 18 60 NA 86 12 70 34 ...
$ density : num 0.999 0.999 0.996 NA 0.996 ...
$ pH : num 3.14 3.37 NA 3.2 3.28 3.32 3.43 3.34 3.46 3.39 ...
$ sulphates : num 0.57 0.71 0.5 0.52 0.59 NA 0.64 NA NA 0.6 ...
$ alcohol : num 11.4 11.5 11.2 9.4 9.8 11.5 11.3 9.2 12.5 10.6 ...
$ quality : int 5 7 4 5 5 6 4 5 6 6 ...